Maria Sharapova defeated unseeded American Coco Vandeweghe on Tuesday to reach the semifinals at Wimbledon for the first time in four years.

Following the loss, the 23-year-old Vandeweghe accused Sharapova of poor sportsmanship during the three-set match. 

Vandeweghe, who was defeated 6-3, 6-7 (3-7), 6-2, claims Sharapova consistently moved around during her service motion

"She was moving around in the middle of my motion on my second serve," said Vandeweghe, per ESPN. "[The umpire] said she didn't believe she was doing it during the motion. I strongly disagreed. Toward the later end of the second set, I said if she has a problem speaking to Maria, if she's too scared to do it, I had no problem speaking to her."

However, Vandeweghe said neither she nor the umpire addressed Sharapova while the match was in progress.

"What I experienced, what I felt from her moving around in between my serving motion was not, I don't think, sportsmanlike, in my opinion," added Vandeweghe. "I try to play as fair as I can. You know, when I felt like it wasn't being reciprocated, that's when I spoke with the umpire for her to deal with."

Sharapova brushed off the accusations in her post-match press conference.

"I mean, it is what it is," Sharapova said. "What she said, I'm not going to argue against her words."

The second set Sharapova dropped to Vandeweghe represented the first set had dropped at the All England Club in the tournament.

The 28-year-old will now face 2015 French Open champion Serena Williams on Thursday.